Brigadier General Karel Rehka is a graduate of Military High School of Jan Zizka in Opava and Military College of Land Forces in Vyskov. He also completed Commissioning Course at Royal Military Academy Sandhurst in Great Britain, Ranger Course in USA, Forward Air Controllers Course in Great Britain, Senior Officers Course, Brigade Staff Course at Military Academy in Brno and General Staff Course at University of Defence in Brno.

After graduation from the Military College of Land Forces in 1997 he held successive posts as a Special Reconnaissance Team Leader and Special Forces Team Leader in the 6th Special Brigade of the General Staff.

From 1999 to 2000 Brigadier General Karel Rehka served as a Reconnaissance Troop Leader in the 6th Reconnaissance Company in Kosovo Force (KFOR). After coming back he left special forces to become a Staff Officer in Foreign Relations Branch in Military College of Land Forces in Vyskov. In the same time he successfully completed extra - mural Master Degree Studies at the college. Subsequently, he served on the position of Forward Air Controllers Team Leader in the 32nd Tactical Air Force Base, a Staff Officer in the 6th Special Forces Group, a Commander of the Special Designation Centre and a Chief of Planning Branch in the 601st Special Forces Group. During this time, in 2004, he was a Deputy Commander Czech SOF Contingent in the Islamic Republic of Afghanistan.

From 2006 to 2009 Brigadier General Karel Rehka served as a Staff Officer in HQ ARRC in Rheindahlen, Germany. During this time (2006-7, 2007-8) he was in the Islamic Republic of Afghanistan as a Staff Officer in HQ ISAF Special Operations Command and Control Element.

Subsequently, Brigadier General Karel Rehka held successive appointments as a Staff Officer in the Directorate of Special Forces and a Commander of the 601st Special Forces Group. During this time he again served in the Islamic Republic of Afghanistan as a Commander of Special Forces Task Force in ISAF (2011).

From 2014 to 2017 he was a Director of Special Forces Directorate of MoD. He was promoted to Brigadier General in 2016.

In 2017 Brigadier General Karel Rehka was appointed to the position of the Deputy Commander of the Multinational Division North East.